Machine for finishing gears



MACHINE Fon FiNIsHING GE'ARs Fled'Dec. 6, 1933 12 Sheets-Shee t 1 Mg l e je 54 57 ,35 l? a @D 5 f5 Y u u s g 5/15 /09 il n, 2l

KlNvlzN-rola E. A.OVERSTEDT MACHINE FOR FINISHING GEARS' INVENTOR S'eltfz, 11941. y E; A. ov-EYRSTDT 2,254,240 l MACHINE FOR FINISHING GEARs n Filed Dec. 6, 1933 l2 Sheets-Sheet 3 TI'ORNEY.

- Sept. 2, 1941. E A. ovERs-rED-r MACHINE FOR FINISHING GEARs l2 Sheets-Sheet 5 Filed Dec. 6, 1933 /afr Sept. 2, 1941.

E. A. OVERSTEDT MACHIE FOR FINISHING GEARS Filed uw. e, 195:5 '12 sheets-sheet s INVENToR fum@ MMM.

ATTORNEYS Sept. 2, 1.941. E. A. ovERsTEDT ,2,254,240

Y MACHINE FOR FINISHING SEARS Filed Dec. 6, 1933 I 12 Sheets-Sheet 7 --V-LL Sept. 2, 1941. E. A. ovERsTED'r 2,254,240

MACHINE Fon FINISHING GMRSV l Filed Dec. e, 193s 12 sheets-sheet a ELE- Sept. 2,A 1941. E. A. ovERsTED'r 2,254,240

- MACHINE Fon FI'NISHING GEARs Filed Dec. 6, 1933 12 Sheets-Shet 9 vmvENT-OR ATTORNEYS.

Sept. 2, 1941. E. A. ovERs-rED-r MACHINE FOR FINISHING GEARS Filed Deo'. 6,v 1933 12 Sheets-Sheet 10 A TTORNEYS.

Sept."2, 1941. E. A. oVERs-rED'r 2,254,240

MACHINE FOR FINISHING GEARS Filed Dec. 6, 1933 12 Sheets-Sheet 11 INVENToR. n

ATTORNEYS.

Eli-

Sept. 2,1941. E. A.ovERsrEDT 'I 2,254,240

MACHINE FOR FINISHING GEARS y Filed Dec. 6, 1933 12 Shiaets-Sheel.y 12

I "Am l N V EN TOR.' l Erf/e5? H Overs Zea.

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A TTORNEY.

Patented Sept. 2, I1941 PATENT OFFICE MACHINE Fon. FINIsmNG GE'ABS Ernest A. Overstedt, Detroit, Mich., assignor, by mesne assignments, to Michigan Tool Compay, Detroit, Mich., a corporation of Delaware Application December 6, '1933, Serial No. l1,097

11 Claims.

My invention relates to machines andparticularly to a machine for accurately iinishing roughed out gear teeth to accurate form.

Heretofore a grinding operation was usually' utilized for nishing gears lto accurate dimensions which was slow and costly. and lapping machines were also employed in an attempt to produce accurate vtooth forms. While lapping, grinding and burnishing were utilized with success on certain types of gears,v none of 'these operations solved the problem of accurately iinishing gears in an exceeding rapid manner as accomplished by the present machine.

The machine utilizes the rack type principle flor generating true involute forms on the teeth of gears in an exceedingly rapid manner.` A tool is constructed of a plurality of blades upon the top edges of which teeth are providedhaving Y iat sloping surfaces which are grooved to provide closely adjacent cutting edges. 'I'he cutting edges are disposed vertical of the tool, normal to the length of the tooth, to eliminate any machining due to the rolliof the gear when the gear and tool are operated in synchronism with each other. Various methods may be utilized for providing a. lateral movement between the gear and tool when operated in meshed relation, such as providing a lateral movement to the tool or to the gear, but I prefer to oiset the axisof the gear to the plane of operation of the tool so as to produce a lateral slippage between the teeth of the tool and those of the gear while they are relatively operated. This is eected by mating a spiral gear with a spur tool or. a spur gear with a spiral tool or when the angle between the plane of operation of the gear and` tool is to be less than the spiral lead of the gear teeth then the spur gear may be mounted on a spur tool of shorter lead.

The present machine embodies the movement of the tool in reciprocation to rotate the gear during the time the gear is fed downwardly onto the tool under a predetermined pressure. The machine may be set to have the tool reciprocate a predetermined number of times or may be set to have the tool reciprocate until the gear has been machined to a desired diameter, after which'the machine ceases to operate. During the machining operation the gear is preferably fed laterally across the tool to produce even wear on the tool teeth. The control illustrated is hydraulic, the uid. which is preferably oil. is pumped by suitable mechanism into a cylinder to reciprocate the tool and into various other Burnishing machine which will be later described. An electric motor is preferably employed for driving a pump associated with the hydraulic mechanism but it is to be understood that the various movements of the machine elements could be obtained by mechanical rather than hydraulic means.

Accordingly, the main objects of my invention are, to construct a machine having a bed whereon a cutting tool may be reciprocated; to provide a head for the machine in which a gear to be machined may be mounted and which is constructed to be adjustable to have the lead 'of the teeth of the gears mesh with the teeth of the rack so that their planes of operation will be intersecting: to feed the gear into the tool with a predetermined pressure; to feed the gear and tool laterally, relative to each other, to produce uniform wear on the tool teeth; to provide a control mechanism for the machine which may permit the tool to reciprocate a predetermined number of times or which vmay feedthe gear.

into the tool until a desired gear diameter is reached, after which the machine is stopped; f and, in general. to provide a machine for accurately nishing gears which is simple in operation, rigid in construction and economical of manufacture.

O ther objects and features of novelty of my invention will be either speciilcally pointed out 30 or will become apparent when referring, for a better understanding of my invention, to the following description taken in conjunction with Fig. 5 is a sectional view of the structure illus-I trated in Fig. 3, taken on the line 5--5 thereof,

Fig. 6 is an enlarged sectional view -of the structure illustrated in Fig. 2, taken on the line -LS thereof,

Fig. 'l is a sectional view of the structure illustrated in Fig. 6, taken on the line 1-1 thereof,

Fig. 8 is a side elevational view of the structure illustrated in Fig. 6 with the casting in section,

cylinders to effect the complete operation of the Fig. 9 is an enlarged sectional view of the gear carrying head of the machine illustrated inl Figs.

1 and 2,

Fig. 10 is a sectional view of structure illustrated in Fig. 9, taken on the line lll thereof,

Fig. 11 is a sectional view of the structure illustrated in Fig. 9, taken on the line lI-II thereof,

Fig. 12 is an enlarged view, in elevation, of the mechanism enclosed by the base of the machine, with the base cover removed. r

Fig. -13 is an enlarged sectional view of a bleeding valve employed on the machine illustrated in Figs. 1 and 2,

Fig. 14 is a broken rear perspective view of the machine illustrated in Fig. 4, taken from the opposite corner thereof,

Fig. 15 is a View in elevation of a head for the machine illustrated in Figs. 1, 2 and 3, showing a modified form thereof.

Fig. 16 is an enlarged sectional view of the structure illustrated in Fig. 15, taken on the line IS--IS thereof,

Fig. 17 is a sectional view of the structure illustrated in Fig. 16, on the line lI-ll thereof,

Fig. 18 is an enlarged sectional view of the structure illustrated in Fig. 16, taken on the line I8--l8 thereof,

Fig. 19 is an enlarged sectional view of the structure illustrated in Fig. 16, taken on the line IS-l! thereof,

Fig. 20 is a plan View of a cam shown in the structure illustrated in Fig. 16.

Fig. 21 is a plan view of a cam which mates with the cam illustrated in Fig. 20, and

Fig. 22 is a broken diagrammatic view of the circulating system to be employed with the head actuating device illustrated in Figs. 15 and 16.

In the drawings, I have illustrated a machine for actuating a tool in reciprocation for rotating a gear to be accurately finished. The tool is of the rack type. fabricated from a plurality of like blades which are accurately constructed, having teeth on the ends thereof, the sides of which are plane surfaces disposed in predetermined angular relation and provided with a plurality of juxtaposed grooves, providing lands having cutting edges on each side which are capable of machining in opposite directions. 'Ihe plane of operation of the tool and the gear to be machined are angular-1y disposed when the teeth of the gear are mated with those of the tool, to effect a lateral slippage between the mated teeth sides during the time the gear and tool are relatively actuated.

In view of the vertical disposition of the cutting edges on the sides of the teeth of the cutting tool, no cutting is effected due to the roll of the gear in synchronism with the tool and cutting is only produced in the presence of a lateral slippage between the teeth. The method of operation between the teeth of the cutting tool and the gear, to produce an accurate generation of the gear teeth flanks, has been clearly set forth, described and claimedin the copending application of William F. Dalzen, Serial Number 554,193, filed July 31, 1931, and assigned to the assignee of the present invention.

'I'he machine disclosed in Figs. 1, 2. 4 and 14 is of the hydraulically actuated type, and while reference will be had only to this type of operating mechanism, it is to be understood that the same results may be obtained mechanically, electrically or by other well known operating means, or a combination thereof. Hydraulic mechanism is disposed in the base of the machine and em- 75 tion, a spur type of gear would be mounted on a' ployed to actuate the tool in reciprocation and to eifect the feeding of the head, supporting theV lable and predetermined pressure.

gear to be machined, toward the tool under suit- Control mechanism is provided for eiiecting the reciprocation a predetermined number of times, which may be varied at the will of the operator, to regulate the number of cycles of operation of the tool on a gear, after which the machine automatically ceases operation. Suitable means is provided for feeding the head laterally of the tool to advance the gear thereacross to produce even wear on the tool teeth. As a further modified form of the device, a second head is illustrated which may be employed for controlling the feeding of the gear into the rack so as to have the machine continue to operate until a desired gear diameter is produced.

A T-shaped base 25, has a front portion 28 which encloses an oil gear mechanism 39 and embodies ways 21 upon which a tool carrying table 28 is reciprocated. A central rearwardly extending portion 2l supports a pillar 3| upon which a gear supporting head 32 is adjustably secured. The pillar 3l is adjustable forwardly and rearwardly upon the base portion 29 and is clamped in fixed adjusted position by a plurality of bolts 3l. A slide 34 is carried on the front face of the pillar 3i to adjustably support the head 32 a set distance 'above the table 2l. The hand wheel 35 operates a lead screw (not shown) by which the slide 3l is adjusted after which it may be clamped in fixed relation to the pillar 3l by a plurality of bolts I6. In this manner, through the forward and rearward movement of the pillar 3l and the vertical adjustment of the slide 34, the head 32 is positioned over the tool carrying table 28.

The table 2l has a tool 31 bolted or otherwise secured thereto to reciprocate therewith. The tool 31 isinthenatureofarackmadeup ofa plurality of like blades 3l upon the faces of which a plurality of closely adjacent cutting edges are disposed. As pointed out hereinabove, the blades and the method of use is described and claimed in the above mentioned eopending application and will not be described in detail herein.

The hydraulic mechanism Il, illustrated in Fig. 12, and disposed in the base portion 2B of the machine, is driven preferably by an electric motor 4| attached to or disposed adjacent to the base of the machine. Two independent but unit constructed cylinders I2 and 43 are secured to the underside of the table 2l to be supported and carried thereby on the ways 21. Conduits Il and 45 are sealed into the ends of the cylinders I2 and 43 respectively, which are disposed in opposite directions and which produce the reciprocation of the table 28 through the introduction of pressure into the conduit M alternately with the introduction of pressure into the conduit I5. Suitable valve means and control therefor for regulating the alternate introduction of pressure between the conduits will be described more fully hereinafter.

The head 32 carries a gear supporting frame 46 which is angularly adjusted relative to the' head by the actuating of a clamping device Il. By means of this adjustment, the gear to be machined has its axis of rotation adjusted to the proper degree of angularity with the plane of movement of the tool 3l to have the teeth of the gear and those of the tool accurately mated. It will be understood that for obtaining such relaspiral tool and a spiral type of gear would be mounted on a spur tool, or a spiral tool of shorter lead. In any case the' mounting should be such that a' proper degree of angularity is present between the plane of rotation of the gear and the plane of operation of the tool. This degree of angularityshould preferably be less than 30. An angularity between 3 to 20 has produced very satisfactory results. Once however the tool is constructed for a particular gearfthe angularity becomes a fixed quantity so as to have the teeth of the gear accurately mate with the teeth of the tool. Referring to Fig. l, a gear 48 is clamped to ay shaft 49 which is disposed between a fixed center 5| and a longitudinally movable center 52 for rotation. The pivot 52 is adjusted forwardly and backwardly relative to the shaft 49 by a hand wheel 53 to permit the gear to -be removed and a gear to be machined installed, after which the movable center 52 is retained in locked position by a clamping screw operated by a hand wheel 54.

During the relative movement of the gear 48 and the cutting tool 38, oil is freely pumped onto the tool through the conduit 55. The oil washes out the chips between the teeth of the lcutting tool, lubricates the lands of the teeth of the tool to eliminate any friction and a burnishing operation from being produced thereby, and prevents any heat being generated in the tool.

The oil flows over the tool 38 into the table 28 into pockets 56 thereof, as clearly disclosed in Fig. 5. A considerable amount of the chips produced during the machining operation are retained by the pockets 56 and the oil is conducted therefrom through a spout 51 into a trough 58 disposed on the back side of the base portion 26 of the machine as illustrated in Figs. '4 and 5. A pipe 59 extends from the trough 58 into a sloping receptacle 6| to have any of theI chips carried therethroughvdeposited in the bottom of the base 26 of the machine. A screen 62 is disposed parallel to the sloping wall tozthe receptacle 6| and prevents the chips from passing to the front part of the machine, as illustrated clearly in Fig. 5. A suitable cover 63 is provided for enclosing the receptacle 6| and the pipe 59, which provides 3 trolled. A locking handle` 69 retains the handle 68` in adjusted position.

12 therefor through which a shaft 13 projects, i

supported on a bearing bracket 14. 'I'he shaft 13 is keyed to an arm 15 which operates a pull rod 16 illustrated in Figs. 8 and l2. The purpose of the mechanism is to move the rod 16 outwardly from the drawing through the counterclockwise movement of the arm 15 and to lock the arm in moved position for a predetermined number of strokes of the machine. The movement of the rod 16 causes the table 28 to be actuated in a manner-.which will be described hereinafter. The table will continue to operate until the rod 16 is released through the clock-Wise movement of the arm 15 which is controlled by theadjustment mechanism 66.

Upon the shaft 13 a collar 11 is mounted by a key 18 and screw 19 in xed relation thereto. An extending arm 8| is provided on the co1- lar 11 on the upper end of which a pivoted tripping and locking detent 82 is mounted. The extending arm 83 on the detent 82 functions as a latch for engaging a hardened sov plate 84 on a cast boss 85 provided on thehousing 1|. When the latch 83 engages the hardened` plate 84, the arm 8| retains the shaft 13 and arm 15 in counter-clockwise rotated position to retain the shaft 16 in moved position.

Bearing surfaces 86 are provided on the inner face of the collar 11 upon which two ratchet wheels 81 and 88 are rotatably mounted. I'he ratchet Wheels have teeth 89 thereon which are disposedin the opposite direction and are retained in fixed relation to each other by rivets 9|. A suitable spring 92 engagesA the teeth of the-ratchet wheel 88 for preventing the counterclockwise rotation of the ratchet wheels. Front-l wardly of the bearing surface 88 on the collar 11 an extension 93 is provided by whichthe collar and shaft are moved to latch position.

an entrance to the base of .the machine for the removal of the chips.

A-pipe 64 extends into the front side of the oil reservoir where strained or filtered oil will be present to be pumped through the conduit over the tool 38,` as above described. While I specify that the element 62' is a screen. it will be understood that a suitable filter element could be employed when found necessary. The ways 21 upon which the table 28 reciprocates are prefera-bly provided with a plurality of rollers (not shown) upon which the table 28 contacts through the projecting angular shaped portions 65, to rollv thereon.

Referring to Fig. l, a suitable control mechanism 66 isv disposed on the front side of the base 26 having a handle 61 thereon by which the operation of the machine is controlled.v The mechanism may be set to produce a predetermined number of reciprocations to the tables 28 after which the table is automatically stopped. It is only necessary for the operator once themechanism is adjusted to move the handle through a small arc to have the machine commence operation, after the completion of which the machine will automatically stop A handle 68 is provided on the oil gear mechant-...am 39 by which the speed of operation of the trol in reciprocation is con- On the front end of the shaft 13, l'. have mounted a second collar 94 which is rotatable on the shaft and which has an extension which advances toward and engages the extension 93 to rotate the collar 11 and the arm 15 in counterclockwise direction topa position vto permit the latch 83 to engage the hardened plate 84 of the cast boss 85.

AUpon the collar 94 is mounted a collar 96 for rotational movement, having thereon a projecting arm 91 upon which a ratchet finger 98 is mounted to mate with the teeth of the ratchet Wheel 81, biased into engagement with the teeth thereof by a spring 99. The handle 61 is provided with an inwardly projecting lug |0| which engages the portion A|02 of the finger 98 to compress the spring 99 and raise the finger 98 out of engagement with the teeth 88 of the ratchet wheel 81. The handle advances the ratchet iinger 98 and the arm 91 as it is moved counterclockwise until the extension 95 on the collar 94 engages the extension 93 on the collar 11 to move the rod 16 to starting position. The handle is then returned to initial position.

A housing |03 extends upwardly from the housturn it to its initial position. The upper end of the slide extends inwardly, at |01, and is provided with a roller |08 which is contacted by a cam (not shown) on the side of the machine for moving the slide downwardly once during a complete cycle of movement, that is to say, a forward and yback movement of the table 28.

The clockwise movement of the ratchet wheels 81 and 88 causes the arm 91 and the ratchet nger 98 to be revolved in a clockwise direction a predetermined angular amount for each reciprocation of the slide. The end |02 of the ratchet linger 98 strikes an extending lug |09 of the detent 82 and raises the latching finger 83 from contact with the hardened plate 84 to effect the release of the arm 8|, shaft 13, arm 15 and r'od 16 to permit the reverse movement of the rod 16 to shut down the machine. l

By positioning the handle 61 relative to the collar 94 through the adjustment of screws the extension on the handle is adjusted relative to the extension 95 which thereby regulates the position of the finger 98 relative to the lug |09, to control the amount of lclockwise movement of the ratchet wheels 81 and 88 required to have the end |02 of th-e cam finger 98 strike the lug |09 to stop the machine. In this manner any number of strokes can be produced to the table 28 before the table is 'stopped and th machining operation completed.

Referring to Figs. 9, and 11, I have illustrated'the head adjusting mechanism 32 which is employed to feed the gear a predetermined amount toward the tool, once during a'complete cycle of movement of the table. The slide 34 has a frontwardly projecting housing ||2 having dovetailed ways ||3 thereon which support a frame ||4 for lateral movement. vThe frame ||'4 is provided with a separate bearing'surface ||5 to permit the frame to be assembled on the ways H3. The housing ||2 has a slot ||6 therein through which a boss ||1 extends and which is secured to the frame 4. A conical roller ||8 is carried by the bossI ||1 in engagement with a cam wheel ||9, illustrated more clearly in Fig. 10.

The cam wheel ||9 is mounted `on a shaft I2| which is geared through suitable gearing to a shaft |22 mounted for rotational movement on the housing ||2, as illustrated in Fig. 2. A ratchet wheel |23 is fixed to the shaft 22 and is actuated by a pawl |24 mounted o n an extension |25 of a swinging arm |26. The arm isprovided with an extensible finger |21 which may be adjusted on the arm |26 relative to the position of the gear carrying element 46 on the table 28. An adjusting screw |28 is mounted on the arm |26 to control the clockwise swinging movement of thearm. K

An adjustable boss (not shown) is carried by the rear side of the table 28 for engagement with the finger |21 lto move the arm |26 in counterclockwise direction for advancing the ratchet wheel |'23 one or more teeth during each cycle of reciprocation of the table. In this manner the cam wheel ||9 is operated to very slowly move the frame ||4 in oscillation laterally of the plane of movement of the rack. 'I'his movement carries the gear ba'ckwardly and forwardly across the face of the teeth of the tool for the purpose of distributing wear evenly thereover. for the opening adjacent to the cam wheel.||9 which is retained by lock and handle |3|.

The frame I|4 is provided with a housing |32 at the top in which a support 33 for the head 32 is retained on a cam slide |34. Cam engaging bearing elements |35 are carried by the supporting element |33. The slide |34 is actuated by a piston rod |36 which is fixed thereto and which is bearinged in the frame ||4 by the threaded collar |31. The piston rod |36 has a piston thereon (not shown) which is encompassed by a cylinder |38 having an inlet port |39 and an outlet port |4| communicating with the interior of the cylinder. vWhen the fluid ahead of the piston is bled from the port |4|, the cam slide |34 is moved to the right, as viewed in Fig. 9, to cause the supporting element |33 and the head 32 to be moved downwardly. When pressure is introduced into the cylinder through the port |4|, the cam slide |34 is moved to the left as viewed in Fig. 9, and the supporting element |33 for the head 32 is movd to raised position, raising the gear from the tool. When a new gear is placed in the head, a pressure in introduced ahead of the piston through the port |39 to move the cam slide |34 to the right, as viewed in Fig. 9, to force the supporting element |33 and head 32 downwardly to force the gear into contact with the tool under a predetermined pressure. For eiecting this feed at a constant pressure, suitable valve means is provided in communication with the outlet port |4| for bleeding the fluid on the right hand side of the piston from the cylinder to permit the movement of the cam slide |34 to the right to lower the head 32. The bleeding valve will -be described more fully hereinafter.

The supporting element |33 has a head |42 of 'a' shaft 43 supported thereon for rotational movement by a collar |44. The lower end of the shaft |43 has a shoulder bearing end |45 engaged in a shouldered aperture |46 of a threaded stud |41 which is locked to a threaded extending boss |48 of the frame ||4, by a nut`l49. The shouldering of the end in the aperture |46 provides a stop to the downward movement of the head 32 which may be adjusted through the l adjustment of the stud 41 in the boss |48.

A thread |5| is provided on the shaft |43 in engagement with a threaded nut |52 which is fixed to a boss |53 of the frame |54 insupport of the head 32. A worm wheel |55 is fixed to the The housing ||2 has a cover |29 thereon shaft |43 by suitable key means, to be actuated by a worm |56 to adjust the frame |54 independent of the supporting element |33, to thereby regulate the head in accordance withdifferent gear diame- ,bearing |63 is retained against the plate by a screw |64. The inner peripheral edge of the outer face of the nut |64 is provided with a plurality of notches |65 in which a, locking key |66 is engaged when retained in a slot-on the end of the shaft |59 by screws |61.

The, peripheral edge of the frame |54 is grooved .to form a worm wheel |68 which is engaged by a worm |69 which is part of the adjusting device 41. The bottom portion of the plate 46 is provided with dovetail ways |1| upon which a head stock |12 carrying the center 52 and a tail stock .is engagedeoy trip element |96.

|13 carrying the centerA 5| are adjustably clamped. Bythe adjustment of the worm |69, the plate 46 is caused to travel aboutjthe shaft |59 to adiust the head andtail stocks |12 and |13 angulariv relative to the plane of movement of the table 'f8 for the purpose mentioned hereinabove.

The bleeding valve above referred to, is il1`us- |82 connects the two chambers at the opposite ends. Valve seats are formed on the end of the vents |8| and |82 at the point of communication with the chamber |16.

A valve |83 is retained by gravity in sealed relation to the seat of the vent |8|, having' a downwardly projecting guide extension |84 which er tension is provided in the springs to substantially balance the weight, of the head 32.

When the handle 61 is moved to set the catch 63, the rod 16 of the hydraulic mechanism 39, as illustrated in Figure 12, is moved to the left. causing the lever |98 to be moved in a counterclockwise direction about a supporting shaft |99. The opposite end of the lever |98 has a projecting lug 205 disposed thereon and extending inwardly of the machine. The lug is disposed to engage one or the other of the collars 206 and 201 adjustably supported on the end of a shaft 208 extending from the valve |18. When the rod 16 is moved to the left to actuate the lever |98 the piston rod 208 is moved to the right to cause oil to be delivered to the inlet port |39 to actuate the head 32 downwardly. The counter-clockwise rotationof the lever |98 also operates a. Valve 209 retains the valve in aligned relation with the vent and a projection |85 at the top to prevent the valve from sealing the opening through the conduit |19. When oil is introduced through thev conduit |11, it passes through the chamber |15 through the vent |8|, raises the valve' |83, passes through the aperture |19, through the -port |4| to the cylinder |38 to cause'the piston rod |36 to be moved to the left, as` viewed in Fig. 10. This actuates the cam slide |34 to the left to move the supporting element |33 and head 32 upwardly, which occurs when the cycle of operation of the machine is completed.

During the machining operation, as pointed out hereinabove, the fluid is bled from the chamber |38 from the port |4| to permit a constant pressure to be applied to the frame |54 downwardly at the time thek frame |54 is fed downwardly due to the bleeding of the fluidY from the port |4|. This is elected through the vent |82 of the bleeding valve |14 by avalve |86 which engages the seat of the vent |82 and which is biased into sealed position by a spring |81.

A shaft |88 extends upwardly from the sealing valve |86 and has a suitable packing head |89 disposed thereabout to prevent the passage ofV liquid therethrough during the reciprocation of the stem |88. A shouldered nut |9| provided on the threadedend of the stem |88 may be adjusted to regulate the amount of fluid which may pass4 through the vent |82 eachtime the valve |86 is raised. A lever |92 is pivoted at |93 and has a bifurcated end |94 which spans the nut 9| and has an extending leg |95 on its opposite end which The element |96 is pivoted to effect a swinging movement when the table is moved to the left, as viewed in Fig. 13. A stoppin |91 engages the element |96 and causes the clockwise movement of theY lever |92 when the table 28 moves to the right through the engagementof the element |96 with the extension |95 to cause the stem |88 to be raised. The valve |18 is so constructed as to have the conduit |11 function to exhaust any fluid which may be delivered thereto.

The frame A| |4 supports springs 20| which balance the weight of the head 32 supported on the studs 202'which extend through the springs and have adjusting nuts 203 and locking nuts 204 disposed on the end thereof, as illustrated in Fig. 1l. Through the adjustment of the nuts, a propthrough the connection of a piston rod 2| thereof with, a pin 2|2 of the lever. to introduce oil into the conduits 44 and 45 for operating the table 28 in reciprocation.

A lever 2|3 is pivoted at 2|4 to, the bed of the machine, as illustrated in Fig. 1, and a projecting pin 2|5 .on the end thereof is actuated by a cam 2| 6 to rotate the lever 2|3 in a counterclockwise direction. The opposite end of the lever is secured through a link 2|1 to an arm 2|8 which is mounted on a shaft 2|9 which actuates a valve in the oil gear mechanism 39 for controlling the now of oil iirst'through the conduit 44 and then through the conduit 45 to effect the reciprocation of the machine. A sec-- 'face facing in the opposite direction to engage the projecting pin 2|5 for moving the lever 2|3 in a clockwise direction. This shuts on the ilow of oil through the conduit 44 and opens the conduitl 45 to the oil supply. The cams 2| 6 may be set at any spaced distance along the side of the table 28 to control the length of its travel in reciprocation.

The motor 4| of the a belt 22|, a pulley 222 which operates a rotary pump 223 of rthe oil gear mechanism. The rotation of the wheel 222 also drives a pump 224 through a sprocket end chain connection 225 for propelling the oil flow through the conduit on to the tool and gear during operation of the machine. A spring balancing device 226 is connected to the lever |98 for rotating the lever in a clockwise direction when the rod |16'is released from held positionby the release of the lug 85, as illustrated in Fig. `6.

The hydraulic mechanism, including the pump 223 and the valve gearing disclosed in Fig. 12, will not be described further orin detail since the mechanism itself is a patented article and embodies no part ofthe present invention except for its use in operating the various component parts of the machine proper. It has been pointed out hereinabove that the handle 68 controls the flow of oil through the conduits 44 and 45 and the speed of operation of the table 28, the handle 69 being employed to clamp the control handle 68 in any adjusted position.

The hydraulic mechanism is capable of delivering oil under two stages of pressure, the

machine drives through I For operating the machine after the various elements are adjusted, it is only necessary to oscillate the handle 61 once through an arc of movement to commenceoperation. The table will reciprocate a predetermined number of times, as above described, during which time a pressure is applied between the tool and gear and the gear is slowly fed into the tool. The gear is shifted slowly across the tool during the operation to provide for the even wear on the teeth of the tool. After a predetermined number of reciprocations of the tool, the machine automatically stops and the head and gear is raised. It is only necessary to remove the finished gear and place the second gear to be machined in the head after which the movement of the handle `61 again starts the feeding movement to the head and the reciprocation of the table to finish the gear.

In Figs. 15 to 22, inclusive, I have illustrated a modified form of adjusting head 34 which may be employed with the machine hereinbefore described. In this instance the head is so constructed as to feed the gear into the tool until the desired gear diameter is reached, after which the feeding operation is stopped and the machine itself may be stopped or additional strokes may be applied hereto before the machine ceases operation.

The frame ||4 is substantially the same as that illustrated and described in regard to the head construction of Figs. 9, and 1l, with the exception of the construction of the shaft |43 and its accompanying mechanism which will now be described. A shaft 221 has a head |44 thereon which connects with the cam element |33 as described hereinabove. The shaft, however, is shortened and provided with threads 228 which are engaged by a gear 229 actuated by the worm wheel |36 for the purpose of adjusting the frame 23| on the shaft 221 in accordance with the gear diameter to be machined. The extending boss |46 of the frame I |4 has a stud 232 of a cam plate 233 mounted thereon with the cam face disposed upwardly. A boss 234 provided on the frame 23| employed with two ratchet wheels 231 and 238 for the purpose of obtaining a fine adjustment and at the same time having coarse teeth in the ratchet wheels so as to withstand wear.

By having the teeth offset immediately of each other on the two ratchet wheels, advancement of half of the arc subtended by a tooth is effected each time the plunger is reciprocated to the right, as viewed in the figures. To prevent the reverse rotation of the ratchet wheels, the teeth 24| are provided on `the cam plate 236 engaged by a ratchet finger 256 pivoted on the screw 251. A suitable spring 258 bias the finger 256 into engagement with the teeth 24| on the cam plate.

For releasing the cam fingers 25|, 252 and 256,

f' `I have provided a cylinder 259 from which a pishas a shaft 235 of a cam plate 236 retained therein for rotational movement, the cam plate 236 being disposed downwardly. The upper end of the shaft 235 is shouldered to receive ratchet wheels 231 and 236, the teeth of one of which are disposed medially of the tooth of the other wheel. The ratchet wheels are retained in fixed relation to each other by a key 239 and are biased for rotational movement by a spring 241. The cam plate 236 also forms a ratchet wheel by having ratchet teeth 242 thereon, as illustrated'in Fig.

19. It will be noted in Figs. 17 and 18 that the ratchet teeth extend only part way around the ratchet wheels, the purpose of which will be explained hereinafter.

An oil cylinder and piston 243 is disposed on the side of the housing |32 of the frame H5, having a piston extending frontwardly thereof and which is provided with an eye 244 which is secured to a link 245. The link operates a shaft f 246 in rotation to operate an arm 241 the end of which projects in a slot 248 of a plunger 243. The end ofthe plunger 249 carries ratchet wheel fingers 25| and 252 which are pivoted on a pin 253. The plunger ,carries springs 254 and 255 fon. the purpose of biasing the fingers 25E and 2 5 2 into vengagement with the teeth of the ratchet wheels. The two ratchet fingers 25| and 262 are ton rod 26| extends having truncated conical cam .elements 262 and 263 thereon. When the oil gear mechanism is actuated to stop the machine, oil flows into the cylinder 259 to actuate the piston rod 26| downwardly to have the cam elements 262 and 263 engage the projecting ends 264 and 265 respectively of the ratchet fingers 25| and 256. This downward movement causes the fingers 25| and 256 to be moved in a counterclockwise direction out of engagement with the teeth of the ratchet wheel and cam plate, respectively, while at the same time a pin 266 carried by the ratchet finger 25| engages a projection 261 on the ratchet finger 252 to cause it to be rotated sion of the spring 24| causes the ratchet wheels v 231 and 238 and the cam plate 236 to be rotated in counter-clockwise direction to be returned to original position.

In Fig. 22, I have illustrated diagrammatically the oil control mechanism wherein a valve 263 is connected in the system and is reciprocated each time the table is reciprocated, or which may be operated once during a complete cycle of reciprocation of the table. The valve 268 feeds oil first in one end of the cylinder 243 and then in the other for the purpose of reciprocating the piston and rod therein to oscillate the link 245. This oscillation causes the reciprocation of the plunger 249 and causes the ng-ers 25| and 252 to be reciprocated therewith to cause first one and then the other to engage a tooth on one and then the other of the ratchet wheels, respectively, for advancing the shaft 235 and therefore the cam plate 236 in rotation.

When the machine is set to begin operation, the pressure applied thereto through the piston rod |36 will force the head downward until the cam plates 233 and 236 contact with each other. Thus the feed movement is limited through the .cam faces and the feed is obtained through the rotation of the shaft 235, as above described, to rotate the cam faces on each other to provide the feeding movement of the head and the gear. By adjusting the ratchet wheels 231 and 236 on the shaft 235, through suitable means not shown, the degree of downward feed may be limited and which, therefore, may be set to correspond with a desired gear diameter.

The rotation of the shaft 235 will continue until the ratchet fingers 25|-and 252 feed all of' the teeth of the ratchet wheels 231 and 236 thereby and the smooth portion of the ratchet Wheels are disposed adjacent to the ends of the lingers. In this manner the feeding movement ber of strokes may be provided to the tool before the shut down occurs.

A valve 269 is disposed to control the flow of fluid in to the cylinders |38 and 259 for the purpose of retracting one piston when the piston of the other cylinder is advanced. In this manner when the pressure is applied to the head'32 to move the gear downwardly, the cam elements 262 and 263 are retrieved. When the pressure is released from the head 32 to raise the gear through the actuation of piston in the cylinder |38, the piston of the cylinder 259 is actuated to cause the downward movement of the cam elements to trip the ratchet fingers, as above described.

When the machine is operated with the head f as above described in relation with Figs. 16 to 22, inclusive, an exact gear diameter is produced or at least the gear teeth are machined, in accordance with a desired gearV diameter,4 after which no furthermachining is effected. The head is so constructed that it may be adjusted to Avarious gear diameters within predetermined limits, after which the cam feeding mechanism may be adjusted to feed the head only until the predetermined gear .diameter is reached, after which thefeeding movement is stopped. The mauniformly from the crown to the .root of the teeth.

lWhile I have illustrated a machine in which a rack type of tool is employed, it is to be understood in the broad concept' of the invention that circular tools may be utilized to effect the same result in the same manner. An advantage, however, is provided in the rac vtype of tool in that the form on the sides of the teeth are plane surfaces and which thereby produce a true involute form' on the gear teeth. When it is necessary to sharpen the teeth, it only requires a dressing operation of the plane surfaces to produce sharp cutting edges which again generate a true involute form.v When sectors or circular gear shaped tool elements are provided, it is necessary to form on the fianks of the teeth, true or modified involute forms to produce an involute form on the gear. This spirit and scope of my invention, as set forth in the accompanyingv claims.

1. A machine for accurately finishing gears, including in combination, a bed, hydraulic mechanism in said bed, a motor for operating said mechanism, a reciprocable table on said bed, hydraulic means attached to said bed and table and connected to said mechanism, a rack tool on said table, a head above said rack having means for mounting a gear to be machined thereon, and means for moving said head towards said rack.

2. A machine for accurately finishing gears, including, in combination, a bed, hydraulic mechanism in4 said bed, a motor for operating said mechanism, a reciprocable table on said bed, hydraulic means attached to said bed and table and connected to said mechanism, a rack tool cn said table, a head above said rack having means vfor mounting la gear to be machined thereon,

means for movingsaid head towards said rack,`

and means for shifting said rack and work gear laterally of each other. Y.

3. A machine for accurately finishing gears which includes, in combination, a bed, a table reciprocable thereon, a tool on said table, a head mounted above said tool, means on said head for supporting a gear relative to said tool, means responsive to movement of said tool for moving said head downwardly on said tool, andadditional means responsive to movement 'of said tool for shifting said tool and gear laterally of each other.

'4. A machine for accurately finishing gearswhich includes, in combination, a bed, a table reciprocable thereon, a tool on said table, a head mounted above said tool, means on said head for supporting a gear relative to said tool, means for moving said head downwardly on said tool, and means for shifting said tool and gearlaterally of each other, said downward movement and said lateral movement both being controlled byv the table during its reciprocation.

must not only be accurately produced on the tool when constructed, 'but must be produced during each sharpening operation.

Through the use of the hydraulic mechanism, the operation of' the various component parts of the machine are'materia'lly simplied and once' the machine is set up in operation, no difcultv whatsoever is experienced due to the wear or adjustment'of parts. In this type of machine two or more gears a minute may be finished to extremely accurate dimensions which is exceedingly faster than any other device known in the art is able to accurately finish teeth or gears.

While I have illustrated and described but two embodiments of my invention, it will be apparent to those skilled in the art that various changes, omissions, additions and substitutions may be made therein without departing from the 5. A machine for rapidly finishing gears which includes, in combination, a tool for finishing a.. gear, means for driving the `-tool and gear one by the other through a predetermined cycle, a support for said gear adjustable at an angle to the plane of movement of the tool, means for moving said support to move said gear radially into said tool, and means for moving said tool and gear laterally of each other, said radial and lateral movements occurring in increments'during said cycle of operation and in response to said gear and tool driving relation.

6. A machine for rapidly finishing gears which includes, in combination, a tool for finishing a gear, means'for driving the tool andigear one by the other through a predetermined cycle,

a support vfor said gear adjustable at an angle by the relative driving movement between said gear and tool.

7. A machine for finishing gears which includes, in combination, a rack tool, a source of power for driving said tool in reciprocation, a head movable toward said tool, a work supporting element carried by said head and rotatable relative thereto, and means actuated by said y source of' power. for moving said head toward I of each other during the driving of the tool.

9. A machine for accurately finishing the working surfaces of the teeth of roughed out gears, including in combination, a bed, a table mounted for reciprocating movement on said bed, a rack type tool mounted on said table, said tool having teeth conjugate to the teeth to be produced on a gear to be finished, a head disposed above said tool, means on said head for rotatably mounting a gear to be nished in meshing engagement with said tool and means responsive to reciprocation of said table for feeding said head downwardly toward said tool.

10. A machine for accurately nishing the working surfaces of the teeth of roughed out gears, including in combination, a bed, .a table mounted for reciprocating movement on said bed. a rack type tool mounted on said table, said tool having.r teeth conjugate to the teeth to be produced on a gear to be finished, a head-disposed above said tool, means on said head for rotatably mounting a gear to be finished in meshing engagement with said tool, means responsive to reciprocation of said table for feeding said head downwardly toward said tool and means for shifting said head laterally with respect to said tool, whereby to distribute wear uniformly over said tool.

11. A gear nishing machine including in combination, a bed, a table mounted for reciprocating movement on said bed, a rack type tool mounted on said table, said tool having teeth coniugate to the teeth to be produced on the gear to be finished, a head disposed above said tool, means on said head for rotatably mounting a. gear to be finished in meshing engagement with said tool, hydraulic means for effecting reciprocation of said table whereby to produce rotation of said gear. hydraulic means for feeding said head downwardly toward said tool, said last mentioned hydraulic means being controlled by said first mentioned hydraulic means.

ERNEST A. OVERSTEDT. 

